ŠEVELOVÁ, Lenka, Aleš FLORIAN and Jaroslav ŽÁK. Influence of Plunger Stress on Resilient Modulus of Forest Subgrade Soils Obtained from Cyclic CBR Test. Forests. Basel (Switzerland): MDPI, vol. 12, No 11, p. nestránkováno, 1456 pp. ISSN 1999-4907. 2021.
Other formats:   BibTeX LaTeX RIS
Basic information
Original name Influence of Plunger Stress on Resilient Modulus of Forest Subgrade Soils Obtained from Cyclic CBR Test
Authors ŠEVELOVÁ, Lenka (guarantor), Aleš FLORIAN (203 Czech Republic, belonging to the institution) and Jaroslav ŽÁK (203 Czech Republic, belonging to the institution).
Edition Forests, Basel (Switzerland), MDPI, 2021, 1999-4907.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 20101 Civil engineering
Country of publisher Switzerland
Confidentiality degree is not subject to a state or trade secret
WWW URL
RIV identification code RIV/75081431:_____/21:00002201
Organization unit Institute of Technology and Business in České Budějovice
Keywords in English low volume road; pavement; soil; resilient modulus; CBR; cyclic; test; subgrade; subsoil; forest road
Tags KSTR9, RIV21, SCOPUS
Changed by Changed by: Mgr. Nikola Petříková, učo 28324. Changed: 16/11/2021 10:23.
Abstract
The low load-bearing capacity of subgrade soils is typical for forest roads. For the determination of the resilient modulus Mr of unbound natural as well as recycled materials, a laboratory triaxial test with cyclic loading is generally preferred. For low volume roads, including forest roads, an alternative method of the cyclic CBR test, which uses standard CBR devices for repeated loading, is being tested and applied in practice. For forest subgrade soils, the procedure for determining the modulus Mr based on cyclic loading of the specimen to a constant penetration depth of 2.54 mm was verified. This procedure was tested on an extensive dataset obtained from 11 forest roads in the Czech Republic, which was then statistically evaluated. The obtained results showed disproportionately high mean values as well as high random variability. Further data analysis revealed that the reason seemed to be the chosen test methodology. When using this procedure for forest soils, high values of plunger stress can occur, which for many types of soils greatly exceed their maximum load-bearing capacity. As result, the modulus Mr is determined at unrealistically high plunger stress values and in many cases on the disrupted specimen. The necessary solution to this shortcoming is to censor the results of the cyclic CBR test, i.e., to exclude unrealistic values of the modulus Mr determined at plunger stresses exceeding the limit values.
PrintDisplayed: 28/3/2024 10:46